Idle screws question

The air screws on my '83 twin are on the engine side of the carbs, not the air intake side. Which way should I turn to richen the mixture at idle?

Will this effect throttle under load at 2500-3000 rpm? This 750 will only run good with the "choke" pulled either part way or all the way out. Otherwise it stumbles. Once over 4000 it accels fine.

- Stock exhaust -
- Stock air box -
- Uni filter aftermarket filter -
- Advance works fine -
- WG coil mod done -
- New battery -
- 117.5 main jets -
- Rebuilt carbs -
- no needle adjustment clips -
- no air leaks -
- Still guessing -

If they are the same as the 76-80 750 twin airscrews (different carbs though), you screw them out to richen the mixture.